1. Field of the Invention
The invention relates to an inter-mobile body carrier phase positioning device and method in which relative positional relation between mobile bodies is determined.
2. Description of the Related Art
A device for calculating relative position with the use of inter-vehicle communication has already been available, the device including a relative position calculating means using a difference in GPS signal propagation time, which determines a difference between data on GPS signal propagation time with respect to a nearby vehicle and data on GPS signal propagation time with respect to a host vehicle, and solves simultaneous equations in the three or more values of the differences in the GPS signal propagation time thus determined and the relative position, which is the unknown, to obtain the relative position of the nearby vehicle with respect to the host vehicle (see Japanese Patent Application Publication No. 10-148665 (JP-A-10-148665), for example).
In the technology described in JP-A-10-148665, for the purpose of positioning, geometrical equations are formulated that are expressed using the difference in GPS signal propagation time and the direction cosines of the angles formed between axes of the relative coordinate system and the line segment between the host vehicle and a satellite, and the equations are simultaneously solved to obtain the relative position. In such a configuration, however, there is a problem with the positioning accuracy because of the fact that only the GPS signal propagation time with large error is used as the observation data, the fact that the directional cosines of the angles formed between axes of the relative coordinate system and the line segment between the host vehicle and a satellite cannot be accurately determined, etc.